Spectrophotometric determination of nitrogen in small quantities of biological materials.
D000596:Amino Acids / Q000032:analysis*; D008722:Methods; D008832:Microchemistry; D009584:Nitrogen / Q000032:analysis*; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012428:Ruthenium; D013053:Spectrophotometry
D000596:Amino Acids; D000644:Quaternary Ammonium Compounds; D012428:Ruthenium; D009584:Nitrogen